The Coming Green Wave: Ocean Farming to Fight Climate Change
Excerpt (link below):
Oysters also absorb carbon, but their real talent is filtering nitrogen out of the water column. Nitrogen is the greenhouse gas you don’t pay attention to — it is nearly 300 times as potent as carbon dioxide, and according to the journal Nature, the second worst in terms of having already exceeded a maximum “planetary boundary.” Like carbon, nitrogen is an essential part of life — plants, animals, and bacteria all need it to survive — but too much has a devastating effect on our land and ocean ecosystems.
The main nitrogen polluter is agricultural fertilizer runoff. All told, the production of synthetic fertilizers and pesticides contributes more than one trillion pounds of greenhouse gas emissions to the atmosphere globally each year. That’s the same amount of emissions that are generated by 88 million passenger cars each year.
Much of this nitrogen from fertilizers ends up in our oceans, where nitrogen is now 50 percent above normal levels. According to the journal Science, excess nitrogen “depletes essential oxygen levels in the water and has significant effects on climate, food production, and ecosystems all over the world.”
Oysters to the rescue. One oyster filters 30-50 gallons of water a day — and in the process filters nitrogen out of the water column. Recent work done by Roger Newell of the University of Maryland shows that a healthy oyster habitat can reduce total added nitrogen by up to 20 percent. A three-acre oyster farm filters out the equivalent nitrogen load produced by 35 coastal inhabitants (PDF).